Firestone is an in-game companion app for Hearthstone, that includes everything you need while playing. Its main components are:

• an in-game decktracker and overlays for all Constructed modes
• an in-game overlay and live info window for batt
• an in-game overlay for Mercenaries
• a hub to collect and view all kind of stats, both personal and about the general meta, for the main game modes

In-game deck tracker and overlays

This includes information that is common to all deck-based modes (Ladder, Duels, Arena, Tavern Brawl)

• Player decklist tracking

  • Know what is in your deck / hand / board / graveyard thanks to collapsible zones (picture 1, picture 2, picture 3)
  • Dynamically track the effects some cards will have when played (e.g. Tess, Fizzle, Mixtape, etc.)

• Opponent card tracking

  • Shows all the cards they have played
  • You can also import a decklist to populate the contents of their deck if you know what you're playing against

• Opponent hand card tracking

  • Turn at which the card was drawn

  • Shows an icon with the card image if the card in hand is known. It also supports flagging Unknown Mixed Concoctions (picture since 13.6)

  • Shows buffs that the card received

  • Also indicates other statuses, like whether the card has been forged (forged example)

• Counters to recap some critical information

  • Know your total attack on board, next fatigue damage you'll take, how many corpses you have spent this game, etc.
  • A non-exhaustive list can be found on this screenshot
    • Noteworthy mentions: Excavate (picture (missing)), Spellschool (picture)

• Tracks the order in which each minion came into play (which is especially useful to know the order in which your Deathrattles will trigger) (picture)

• Highlights synergies in your deck (picture)

• Quickly see all related cards when mousing over a card in your deck (picture)

• Recaps the game-changing cards that were played, like Luna's Pocket Galaxy or the Passive buffs in Duels (picture)

• Turn timer (picture)

• The app can automatically import the opponent decklists when playing against the AI (Dungeon Run-like modes like Tombs of Terror, Book of Heroes, etc.)

Constructed

Premium features are listed here

App window

• View an overview of all your decks (picture)
  • You can merge two different decks together if you consider they are simply new versions of each other
• View a clean, colorful recap of your deck and its performance and highlight card synergies with a simple mouse-over (picture 1, picture 2)
• View all the best performing decklists of the meta. All filters are available for free, so you can explore the meta that best matches your rank, or instead look at what the top players are playing (picture)
  • You will also see how much dust you need to craft a specific list
• View more detailed info on each deck (picture)
• View aggregated play stats for you and your opponents (picture), as a recap of all your matchups (picture)
  • This can be filtered by deck, format, time frame and rank
• View your ranking evolution across the different seasons (picture)
  • There are two different graphs for the "leagues" and for the "legend" ranks
• In-app deckbuilder. It highlights synergies, and is more reactive than the in-game deckbuilder (picture)
  • You can save your deck for later, or directly copy its code to import into Hearthstone

Overlay

• See mulligan information directly in the overlay. It tells you, for the archetype you're playing, which cards have the biggest impact when kept during mulligan, and how much others keep this card during mulligan (picture). Details about where this data comes from (ranks, sample size) is visible at the bottom of the deck mulligan overview. (since 13.7)
  • Free users can have access to the mulligan overlay info a few times per day, and it is unlimited for premium users

Battlegrounds

Premium features are listed here

App window

• View overview of the meta (picture)
• View detailed stats for each hero, including your own stats (picture 1, picture 2, picture 3)
• View overview of the meta stats for Quests and Rewards (when available) (quests, )
• Graph your MMR evolution over time (picture)
• View a list of recent perfect games (WARNING: currently broken) (picture)
• Battle simulator!
  • Simulate any board positions (picture)
  • You can customize more or less everything. The only thing missing at the moment is the players' hands, which will come later
  • Let the app find the best positioning for you (See RDU using this feature)
  • Export your board to share with friends (and of course import the code in the app)

Overlays

• View the odds to win each battle (picture)
  • You can configure this to only show up once the battle is over
  • You can also see play-by-play examples of how the simulation went for a specific battle (picture)
• Browse all the minions available in the lobby, including their golden versions. They can be grouped by tier, mechanics or tribe (picture)
  • Also includes a current turn counter
• Mouse over the leaderboard to view information about your last opponent, like their last board, when they leveled up or if they had new triples since the last time you fought them (picture)
  • Also quickly see who your last opponent was
• See a recap of your current play session - number of games played, placements, last warbands and MMR changes since your last reset (picture)
• Get various counter widgets that keep track of useful information, for you and your viewers if you're streaming, like the current Blood Gem values (picture), how much more gold you'll get next turn (picture), and more.
• Highlight specific minions in the shop so you don't accidentally miss one you're interested in (picture)
• Show the list of available / banned tribes as a widget. A bit redundant now that you can show the tribes in the minions list itself, but still very visual (picture)
• See achievements completed for each hero during hero selection (picture)
• View the MMR of your opponents (picture 1, picture 2). NOTE: this uses the official leaderboards to do a name lookup; as such, it is not totally reliable, and won't work for low- or medium-MMR players.

BG window

The BG window is another window, ideally used on a second screen, but that can also be displayed as an overlay if you're in a single-monitor setup.

• View stats for each hero when selecting which one to pick (picture)
• View live info on all your opponents (last boards, tavern update timings, buddy upgrades, quests) (picture)
• Get live stats on your game: all players HP graph, warband composition, total warband stats (picture 1, picture 2, picture 3)
• View all your battles from this game (picture)
  • Easily change the minion positioning in any one of them and resimulate it. You can also export it into the app's simulator if you want more control

Duels

Premium features are listed here

App window

• Get an overview of all your runs (picture)
• See an overview of all your decks (picture)
• View details of the deck for each run (picture)
• Browse meta stats for heroes, hero powers and signature treasures for Heroic Duels (picture)
• Browse meta stats for active and passive treasures for Heroic Duels (picture)
  • Both these sections have a lot of filters to filter the data further
• View a list of decks played by the community that reached 10+ wins in Heroic Duels (picture)
  • View the details of a run, including all loot and treasures picked, as well as the starting and final decklists (picture)
  • Here as well, there are tons of filters available
• View a global Duels leaderboard, both for Casual and Heroic (picture). Please note that they only include data of people using Firestone when playing.
• Browse all current card Buckets (picture).
  • You can filter by class
  • Show the offering rate for each card
• The Deckbuilder is similar to the Constructed one, except that it also shows you all the buckets you can be offered later in the run based on the cards you already have in your deck (picture)

Overlays

Note: I'm planning a global revamp of some how the overlay features work, and it's possible (even likely) that most of these will become premium-only. The info will still be available inside the app itself (but you'll need to click a couple of times)

• When selecting a hero / hero power / signature treasure, view their average win-rate, popularity, and how many high-wins decks the app has in store (hero picture, hero power picture, signature treasure picture)
• When building a deck, you can quickly copy the code of a deck that achieved 10+ wins for this hero / hero power / signature treasure combination, as well as browse all these decks if you want more details (picture)
• View the synergies when picking up Treasures between fights (picture)

Arena

Premium features are listed here

App window

• View the list of all your runs, along with your final rewards (TODO: replace the picture with something that has more details once I get to play some Arena)
  • Also see your deck score (picture, starting with 13.7)
• Class Tier List (picture)
• Card stats (picture)
• View a list of recent decks that went to 10+ wins (picture) and view details about their draft (picture) (since 13.7)

Overlays

• While drafting, the first card pick of a run shows the stats for each of the options (picture). The other picks and the class infos can be unlocked with Premium.
• Show the stats for the first card of each draft directly in the overlay (picture)
• Highlight synergies with your deck when mousing over a card while drafting (picture)

Tavern Brawl

App window

• View a recap of each class' winrate for this week's brawl, and quickly copy a deck code to play the brawl with (picture)

Mercenaries

Premium features are listed here

App Window

• View a detailed recap of your mercs progression (see the picture). Most notably, it tells you how many Coins are needed to max each one.
• Get a quick overview of your PvP teams (picture)

Overlay

• While in battle, view a recap of your team, their abilities, equipment and the number of time each skill has been used (picture)
  • Same for your opponent
  • When mousing over an ability, all its synergies are highlighted (picture)
  • Update the speed of the abilities as buffs / debuffs are applied, and lists the current active buffs (picture)
  • Includes the current turn in the battle, as well as the total number of turns since starting the map (picture)
• While playing in PvE, see a recap of the action queue (picture)
• View the list of Tasks tailored to your current team, as well as their current progress (picture).
• You can also automatically create a team for the daily tasks, that will include the favorites you set up in the settings (picture)
• Mousing over a loot when picking a treasure highlights the synergies your team have with this treasure (picture)

Replays

• View a list of all your past games (picture)
  • You can filter by game mode, then each game mode has a set of specific filters
  • You can notably filter by hero for the BG replays, or by hero/deck for constructed
  • You can also search for specific opponents
• You can view a play-by-play replay of all your games (including BG!), either directly in the app or online in your browser (picture)
• For BG games, you can view the recap of the live stats of the game, including the full battle history and the odds for each battle (picture)
  • You can directly import any battle in the simulator and see how you could have positioned your minions differently to improve your odds

Achievements

• View a recap of all the Hearthstone native achievements in an easy-to-browse, reactive view (picture)
• Pin any number of the HS native achievements to view their progress in real-time while in game (picture)
• Try to complete a number of unique achievements that are exclusive to Firestone (picture overview, picture amazing plays, picture bosses)

Collection

Premium features are listed here

• Track your packs opened since you started playing Hearthstone (so including times before Firestone, or the packs you opened on other platforms like mobile) (picture)
  • Also see your five best packs (picture). This however only tracks the packs opened while Firestone was running.
• Track the pity timer for each pack (picture).
  • This only includes the packs opened while Firestone was running, so be careful if you also open packs on mobile
• See an overview of your full collection with highlights of your complete sets (picture)
  • Includes the details on each of your cards, with the total number of copies you have (not limited to x9) (picture)
• Listen to all the sound effects for cards, in any of the Hearthstone-supported languages (picture)
• See an overview all the card backs, and see at a glance how far along you are to having them all (picture)
• Same for the hero skins (picture) and the list of Coins (picture)
  • The skins are available as well for Battlegrounds (picture) and Mercenaries
• Get notifications when you open new cards / second copies (picture)

Profile

• View a recap of your ALL-TIME stats for the various game modes. This includes all platforms (PC, mobile) and the time when you didn't have Firestone running:
  • Ranked (picture)
  • Arena (picture)
  • Battlegrounds (picture)
  • Duels (picture)

Streams

• View a list of all streamers currently playing with the Firestone Twitch extension enabled (picture)

General

Premium features are listed here

• Broadcast your current status on Discord (picture)
• Get notified when it's your turn to play (taskbar icon blinks)
• The app is highly customizable, and almost every feature can be enabled or disabled separately.

Twitch

Firestone comes with an extension for Twitch (you can set it up from the Settings of the app). It gives your Twitch viewers a lot of cool capabilities, listed below.

Constructed

• Interactive decklist, with all the in-app features (related cards, synergies, modern tracker layout that can be enabled) (picture 1, picture 2)
• Mouse over any element of the game area (cards on board, in hand, hero power, weapon) to see a tooltip with the details of the card

Battlegrounds

• Mouse over the opponents on the leaderboard to view the last known information (last known board, tavern update timings, etc.) (picture)
• Quickly see an overview of the status of all players in the lobby (picture)
• Show battle odds (picture)
• Interactive minions list (picture)
• Mouse over any element of the game area (cards on board, in hand, hero power, quests, anomalies) to see a tooltip with the details of the card (picture)

App

• Appear in the Streams tab inside the app to increase your visibility. You only need to play with the Firestone Twitch extension running (picture)